What is Electroforming?

Kirsten C. Tynan

Electroforming is a process for fabricating objects by electrically depositing metal over a base form or mandrel. The process begins with a source of metal that will be used as the coating and a form to which it will be applied. Both are placed in an electrically conductive solution. When a voltage is applied to the metal source and target object, metal is transported through the solution from the positively charged source to the negatively charged target. Over time, metal builds up on the target, thereby fabricating something of the desired shape and thickness.

Electroforming was used in the main combustion chamber of a space shuttle.
Electroforming was used in the main combustion chamber of a space shuttle.

Although it is similar to electroplating, electroforming differs in that it is typically used to fabricate components that are separated from the form. Electroplating, on the other hand, typically involves applying a coating that becomes part of the object to which it is applied. Electroforming also generally involves applying metal to a non-metallic form whereas electroplating more typically involves applying a metal coating to another metal.

Applications of electroforming range widely. Various metals from copper or nickel to more valuable materials like gold and silver may be used. One common use of this process is in the bronzing of a baby’s first pair of shoes as a family keepsake. A very different, but also notable, example is its use in the main combustion chamber of a space shuttle. Jewelry, prosthetic body parts, currency embossing plates, and numerous other items may be fabricated this way.

There are some downsides to using electroforming. Other metalworking processes such as forging, casting, machining, and so on may also be used for similar fabrication tasks and are generally cheaper. Electroforming can also become problematic in fabricating items with sharp angles or deep or narrow grooves. If the form or mandrel to which the metal is applied becomes damaged or degraded, imperfections will be reproduced in the final product. It also takes a long time; the process may also take days or even weeks to achieve the desired thickness.

The benefits of electroforming, however, often make it the best alternative in spite of these drawbacks. This process can achieve a very thin layer of metal without the shrinkage or distortion characteristic of some other metalworking processes. The purity of the metal in the final product is very good. While the process can be lengthy, it is not labor intensive after the initial setup is complete. Electroforming is often the best choice for fabrication of items that require strict tolerances or light weight.

Discuss this Article

Post your comments
Forgot password?